End liner assembly for rotary mill or the like

ABSTRACT

An end liner assembly for a rotary mill or the like in which the wear plates or liner members at the feed end, or the grates and wear plates at the discharge end, are assembled in a plurality of radially compressed pyramided tiers in stacked relation to each other. The radially outer end of the pyramided tiers is supported on the shell plate of the mill or on a filler ring supported thereby. The radially inner end of the pyramided tiers is engaged by a grinding pad(s) carried by a &#39;&#39;&#39;&#39;pinned&#39;&#39;&#39;&#39; liner member(s) or carried by another member(s) fixed with respect to the rotary mill, such as the discharge cone at the discharge end of the mill. The grinding pads are precisely dimensioned to provide the proper radial compression on the pyramided tiers of liner members. A supplemental clamping action on the liner assembly is provided by the lifter bars which are positioned between contiguous circumferentially spaced liner members in partially overlying clamping relation thereto. As an alternative to the use of grinding pads on the pinned liner of other stationary member, a wedge may be inserted in the clearance space between the radially inner end of the pyramided tiers of liner members and the contiguous radially outer edge of the pinned liner or other stationary member.

P'ATENTED sm 4 l9?! SHEETIUF 3 M Dr M P p a 9 l/ c w Z a m a .7 Lv \w \mw my MA WM w i M7 m iii/ 3 9% y I 7 W 1 X g m w M I M 4 fl 5 ya m m r. z4 4 M f United States Patent [72] Inventor Richard E. Sabaski HalesCorners, Wis. 2 1] Appl. No. 872,294 [22] Filed Oct. 29,1969 [45]Patented Sept. 14, 1971 [73] Assignee Allis-Chalmers ManufacturingCompany Milwaukee, Wis.

[54] END LINER ASSEMBLY FOR ROTARY MILL OR THE LIKE 17 Claims, 9 DrawingFigs.

[52] U.S. C1. 241/70, 241/181, 241/284, 241/300 [51] 1nt.Cl. B02c 17/22[50] Field of Search 241/70, 181-183, 284, 298-299, 300

[56] References Cited UNITED STATES PATENTS 229,577 7/1880 Alsing241/182 1,562,791 11/1925 Ruth 241/181 1,690,493 11/1928 Marcy 241/181 X3,211,387 10/1965 Russell 241/183 X Primary ExaminerDonald G. KellyAttorneysRobert C. Sullivan, Robert B. Benson and Arthur M. StreichABSTRACT: An end liner assembly for a rotary mill or the like in whichthe wear plates or liner members at the feed end, or the grates and wearplates at the discharge end, are assembled in a plurality of radiallycompressed pyramided tiers in stacked relation to each other. Theradially outer end of the pyramided tiers is supported on the shellplate of the mill or on a filler ring supported thereby. The radiallyinner end of the pyramided tiers is engaged by a grinding pad(s) carriedby a pinned liner member(s) or carried by another member(s) fixed withrespect to the rotary mill, such as the discharge cone at the dischargeend of the mill. The grinding pads are precisely dimensioned to providethe proper radial compression on the pyramided tiers of liner members. Asupplemental clamping action on the liner assembly is provided by thelifter bars which are positioned between contiguous circumferentiallyspaced liner members in partially overlying clamping relation thereto.As an alternative to the use of grinding pads on the pinned liner ofother stationary member, a wedge may be inserted in the clearance spacebetween the radially inner end of the pyramided tiers of liner membersand the contiguous radially outer edge of the pinned liner or otherstationary member.

PATENTEDSEPMIBII 3504637 SHEET 2 UF 3 Q A M m. Q Map M W QM M PATENTEDSEPI 41971 SHEET 3 OF 3 LAWN 2) mm 7 8% I w 17M 2? C.

J /EK R/MM FOR ROTARY MILL OR TIIE LIKE BACKGROUND OF THE INVENTION 1.Field of the Invention This invention relates to rotary grinding millsor the like and more particularly to an end liner assembly for use insuch mills.

2. Description of the Prior Art Large grinding mills of the typeutilized for grinding ore or the like such as ball mills, rod mills, ormills of the autogenous type, are all conventionally provided on theinterior thereof at both the feed end and discharge ends thereof withliner or wear plate assemblies, such liner assemblies, except on rodmills, generally being provided in combined relation with lifter barswhich serve to lift the material being ground as the grinding millrotates.

In prior art constructions for grinding mills utilizing end liners withcooperating lifter bars, the liner members or wear plates of the endliner assemblies when not physically held by a through bolt to astructural member and the lifter bars were generally so structurallyinterrelated to each other that if a lifter bar were to become detachedfrom its mounting or loose in its mounting, the entire endliner assemblywould be affected almost immediately, as in a chain reaction. Forexample, in prior art constructions, if a lifter bar or series of lifterbars were to fall out, the liner members or wear plates would also fallout almost immediately thereafter.

A further disadvantage of the prior art end liner construction is thatin the prior art it was the practice to provide grinding pads on theindividual wear plates or liner members constituting the end linerassembly. These grinding pads on-the plurality of individual linermembers or wear plates were physically adjusted, as by grinding of theindividual grinding pads, to ensure placement of the liner members intoparticular fitted or dimensioned locations.

END LINER ASSEMBLY SUMMARY OF THE INVENTION Accordingly, it is an objectof this invention to provide an end liner assembly for use in grindingmills or the like in which the individual liner members or wear platesconstituting the liner assembly do not depend on the lifter bars as aprimary means for holding the liner assemblies in assembled relation, asin prior art constructions, but in which the lifters provide only asupplemental holding action on the liner members.

It is another object of the invention to provide an end liner assemblyfor use in grinding mills or the like in which the wear plates or linermembers constituting the end liner assembly do not require the use ofindividual grinding pads on the individual liners or wear plates.

It is another object of the invention to provide an-end liner assemblyfor a grinding mill or the like in which the liner members or wearplates may have straight edges ratherthan arcuate edges at the radialends thereof which allows for a more economical casting from the foundryand which permits easier inspection thereof by means of a template.

It is still a further object of the invention to provide an end linerassembly for use in a grinding mill or the like which permitsreadjustment of the number of wear plates or liner members when awearing pattern has been established in the grinding mill.

A further object of the invention is to provide and end liner assemblyfor a grinding mill or the like in which the wear plates or linermembers do not have to be as precisely dimensioned in a circumferentialdirection as in the prior art, thereby permitting more economicalmanufacture of the wear plates or liner members than in the prior art.

It is still a further object of the invention to provide an end linerassembly for use in a grinding mill or the like in which the castingscomprising the liner members or wear plates cannot shift during runningconditions of the mill.

In achievement of these objectives, there is provided in accordance withthis invention an end liner assembly for a rotary mill or the like inwhich the wear plates or liner members at the feed end, or the gratesand wear plates at the discharge end, are assembled in a plurality ofradially compressed pyramided tiers in stacked relation to each other.The radially outer end of the pyramided tiers is supported on the shellplate of the mill or on a filler ring supported thereby. The radiallyinner end of the pyramided tiers is engaged by a grinding pad(s) carriedby a pinned" liner member(s) or carried by another member(s),fixed withrespect to the rotary mill, such as the discharge cone at the dischargeend of the mill. The grinding pads are precisely dimensioned to providethe proper radial compression on the pyramided tiers of liner members.

A supplemental clamping action on the liner assembly is provided by thelifter bars which are positioned between contiguous circumferentiallyspaced liner members in partially overlying clamping relation thereto.

As an alternative to the use of grinding pads on the pinned liner orother stationary member, a wedge means may be inserted in the clearancespace between the radially inner end of the pyramided tiers of linermembers and the contiguous radially outer edge of the pinned liner orother stationary member.

Further objects and advantages of the invention will become apparentfrom the following description taken in conjunction with theaccompanying drawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in longitudinalsection of a grinding mill incorporating an end liner in accordance withthe invention at both the feed end and at the discharge end of thegrinding mill;

FIG. 2 is a view taken along line Il-Il of FIG. 1 showing the end linerassembly in accordance with the invention at the feed end of thegrinding mill;

FIG. 3 is an enlarged view in longitudinal section, similar to the viewshown in FIG. 1, of the feed end of the grinding mill;

FIG. 4 is a view taken along line IV-lV of FIG. 2;

FIG. 5 is a view similar to FIG. 4, of a modified mounting arrangementfor the lifter bar;

FIG. 6 is a view taken along line VIVl of FIG. 2;

FIG. 7 is a view taken along line VII-VII of FIG. 1 showing the endliner assembly at the discharge end of the grinding mill;

FIG. 8 is a view similar to FIG. 6 but showing a modified embodiment ofthe invention; and

FIG. 9 is a view similar to FIGS. 6 and 8 but showing another modifiedform of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings,and more particularly to FIGS. 1-6, inclusive, there is shown a grindingmill generally indicated at 10 including a shell generally indicated at12 comprising a cylindrical shell plate 14 to the respective oppositeaxial ends of which are rigidly attached shell flanges l6 and 16. Shellflanges 16 and 16' have ribs 18 rigidly secured thereto or integraltherewith. As best seen in FIG. 3, a shell flange 16 is rigidly secured,as by bolts 20 and nuts 21 to the end plate or head 22 which is integralwith the trunnion 24 upon which the mill I0 is supported for rotation bybearing 26. The shell flange 16' is similarly secured to the end plateor head 22 at the discharge end of the mill. The trunnion 24 at theleft-hand of the view of FIG. 1 is hollow and constitutes As best seenin FIG. 2, a filler ring generally indicated at 36 v and comprising aplurality of circumferentially extending arcuate segments such as thoseindicated at 36a, 36b and 360 is positioned contiguous the radiallyinner surface of the cylindrical shell plate 14. The inner surface ofthe mill is preferably suitably coated or covered with a rubberlikebacking material indicated at 38. Each of the filler ring segments suchas 36a, 36b and 36c is provided on its radially outer surface with aplurality of circumferentially spaced steel pads 40 which are preferablywelded to the radially outer surface of the filler ring segments. Therubber backing material 38 is cut away at the locations of the steelpads 40 so that the radially outer surface of the respective steel padsis in direct abutting contact with the metal surface of shell plate 14.The radially inner surface 42 of filler ring 36 provides a rigidfoundation on which the liner sections or wear plates or the linerassembly are mounted.

In accordance with an important aspect of the invention, a plurality ofliner members or wear plates 44 such as those indicated at 44a-44i, inFIG. 2 are mounted on the radially inner surface of filler ring 36. Theliner members or wear plates 44 are made of a hard metal having goodwearing characteristics. It will be noted that the liner members or wearplates 44a, 44b and 44c define one row of radially pyramided wearplates. The radially outer end of the row of wear plates just describedabuts against the filler ring segments 36a and 36b and the radiallyinner end of the row of wear plates just described abuts against thegrinding pad 47 of what will be referred to as a pinned wear plate 46 tobe described more fully hereinafter, which is rigidly anchored to theend plate or head 22 of the grinding mill. Similarly, the liner membersor wear plates 44d, 442 and 44f define another row of radially pyramidedwear plates which abuts at the radially outer end thereof against thefiller ring segment 36b, and which abuts at the radially inner endthereof against the grinding pad 50 of the pinned liner 48 which isrigidly anchored to end plate 22 of the grinding mill. Similarly, thewear plates or liner members 44g, 44h and 441' lie in a radial line inpyramided relation to each other, with the radially outer end of theradial line of wear plates just described abutting against the tillerring segments 36b and 36c and with the radially inner end of the radialline of wear plates just described (that is the radially inner end ofwear plate 441' abutting against the grinding pad 54 of the pinned liner52 which is rigidly anchored to end plate 22.

As best seen in the view of FIG. 3, each of the pinned liner members orwear plates such as 46, 48 and 52 is rigidly secured as by a pair ofbolts 56 and mating nuts 58 to a rigid structural member such as thehead or end plate 22 of the grinding mill. In effect, in each radiallyextending row of liner members or wear plates, the liner members or wearplates such as 44a, 44b and 440 are pyramided upon each other in aradial line, with the radially outermost edge of the wear plates in thegiven radial line of wear plates, such as the radially outer edge ofwear plate 440, resting in firm engagement with a rigid structure suchas the radially inner surface 42 of the filler ring 36, and with theradially innermost edge of the radially pyramided line of wear plates orliner members 44a, 44b and 440 being held in place by a grinding padsuch as grinding pad 47 on the pinned liner member 46. Each radiallypyramided row of wear plates around the 360 of the liner or wear plateassembly generally indicated at 30 is mounted in the manner justdescribed for the three radial rows of wear plate or liner members shownin the fragmentary view of FIG. 2. Each row of radially pyramided linermembers is circumferentially spaced from the radial rows of linermembers contiguous thereto to accommodate the lifter bars 60. A lifterbar 60 is interposed between each pair of liner members or wear plateslying in contiguous radial rows.

Referring now to FIGS. 2 and 4, the plurality of lifter bars eachgenerally indicated at 60 are positioned between respective pairs ofcircumferentially spaced contiguous liner members or wear plates. Thus,for example, a lifter bar 60a is positioned between the two wear plates44a and 44d, and another lifter bar 60d is positioned between the wearplates 44d and 44g. In a similar manner, a lifter bar 60b is interposedbetween the wear plates 44b and 44e, and another lifter bar 60c ispositioned between the wear plates 44e and 44h. Another lifter bar 600is interposed between the wear plates 44c and 44f and still anotherlifter bar 60f is interposed between the wear plates 44f and 44i. Anarrangement similar to that just described extends around 360 of theliner assembly.

Referring to FIG. 4, it will be noted that each lifter bar includes aflat axial end portion 62, a pair of diverging axially extending taperedsides 64 which terminate in substantially straight axially extendingwall portions 66 which are respectively bounded at their axially innerends by circumferentially extending flat portions 68 bounded byconverging axially extending tapered portions 70 which terminate at aflat axial end portion 72. Each of the liner members or wear plates suchas 44e and 44h is provided with a steplike portion defined by theaxially extending edge 74 and by the circumferentially extending flatedge 76. A tapered axially extending edge 78 extends from the boundaryof edge 76. The opposite flat edges 68 of the lifter bar 60 are adaptedto bear against the corresponding flat edges 76 of the two adjacent wearplates 44e and 44h, for example. The terms axial and circumferential" asused in describing the lifter bar and wear plates relates to the axialand circumferential directions of the grinding mill on which the lifterbars are mounted.

A pair of bolts (FIGS. 2 and 4) extend through a passage in the lifterbar 60 and through a passage in the end flange 16 of the grinding milland is secured in place by a nut 82. The head end of each bolt 80 isreceived in a countersunk recess in the lifter bar, whereby the head endof the bolt is substantially removed from contact with the workload inthe mill. The bolt 80 and nut 82 serve to clamp the lifter bar 60against the edges 76 of the steplike recesses in the respective linermembers or wear plates 442 and 44h, thus providing a secondary holdingmeans for securing the liner members in position.

It will be noted from an inspection of FIG. 4 of the drawings that thelifter bar 60 and the wear plates 442 and 44h are so dimensioned and areso positioned relative to each other that a clearance exists between theaxially extending edges 74 of the respective steplike recesses of themembers 44e and 44h with respect to the contiguous edges 66 of lifterbar 60. Also, there is a clearance between the tapered edges 70 of thelifter bar 60 and the contiguous tapered edges 78 of the liner membersor wear plates 442 and 44h.

An important advantage of the structural cooperative relation betweenthe lifter bar 60 and the wear plates such as 44e and 44h is that theforces exerted upon the lifter bar if the bolt 80 were to loosen wouldcause the lifter bar 60 to slide relative to the wear plates 44e and 44hto take up the clearance between the lifter bar 60 and the wear plates44e and 44h. After sliding to the permissible limit as just described,the lifter would then pivot about a very broad base having a dimensiondefined by the distance between the opposite axial walls 66 of lifterbar 60. This broad base resists pivotal movement and tends to maintainthe lifter bars 60 assembled despite possible loosening of bolts 80.This is in contrast to the prior art construction in which forces on thelifter bar, assuming the bolt or bolts holding the lifter bar in placewere to loosen, cause the lifter bar to pivot in a manner similar to aball and socket joint about a point. Another distinct advantage of alifter bar such as that shown in FIGS. 1-5 is that it permits theholddown bolt 80 to be seated deeper in the lifter due to thecountersunk passage in lifter bar 60 for receiving the head end of bolt80, thereby reducing the shaft length of the bolt. Also, while eachlifter 60 in the illustrated embodiment has been shown as being securedin position by two bolts 80 in spaced relation to each other radially ofthe liner assembly and of the grinding mill, it is also feasible withthis construction, in certain portions of the assembly, to use twolifter bars 44" (not shown) each having one-half the radial length oflifter bar 44 and each held in place by one holddown bolt 80.

The arrangement just described using lifter bars 44" would be related tothe wear pattern of the lifters and may reduce throwaway scrap to aconsiderable extent byv permitting discarding of worn lifters in a moreeconomically efficient manner.

There is shown in FIG. 5 a modified mounting arrangement for the lifterbar 60 which may be used in certain regions of the wear plate assemblyin which'the wear pattern of the workload on the wear plates 44a and 44his such that the wear plates are not substantially worn away in theimmediate region of the lifter bar. In FIG. 5, the lifter bar 60 is thesame as that previously described in the embodiment of FIG. 4. However,the wear plates 44c and 44h do not have the stepped arrangementpreviously described in connection with the embodiment of FIG. 4, butrather are provided only with an axially extending tapered surface 77which merges into an axially extending straight or flat edge surface 79.When the lifter 60 is installed in position with respect to the wearplates 44c and 44h, the flat edges 68 of the lifter bar rest directly onthe outer surfaces 442 and 44h. The tapered surfaces 70 of the lifterbar extend into the recess defined between the tapered surfaces 77 ofthe respective wear plates 44c and 44h. A bolt 80 extends through thelifter bar 60 and is bolted to the flange 16 in the same manner asdescribed in the embodiment of FIG. 4. The bolt in the embodiment ofFIG. 5 passes through the space defined between the straight edges 79 ofthe respective wear plates 442 and 44h.

As has been previously mentioned, the lifter bar 60 in the embodiment ofFIG. 5 is the same as the lifter bar 60 in the embodiment of FIG. 4.I-lowevendue to the fact that the lifter bar 60 in the embodiment ofFIG. 5 is not received in a stepped recess of the wear plates 44c and44h as in the case of the embodiment of FIG. 4, a larger portion of thelifter bar 60 of the embodiment of FIG. 5 projects outwardly beyond thewear plates Me and 44h and into the hollow grinding space of the mill.The construction of FIG. 5 therefore results in a more efficientutilization of the material of the lifter bar, since a greater portionof the lifter bar projects into the work space for effective liftingaction in the embodiment of FIG. 5 than in the embodiment of FIG. 4.Also, the lifter bar 60 of FIG. 5 has a longer useful life than thelifter bar of FIG. 4 since with the mounting arrangement of FIG. 5 alonger time is required for the workload to wear the lifter bar 60 downto a condition in which it must be scrapped. It will also be noted thatthe wear plates 44c and 44h and the lifter bar 60 of the embodiment ofFIG. 5 are so positioned relative to each other that a clearance spaceexists between the tapered edges 70 of the lifter bar 60 and theadjacent tapered edges 77 of the respective wear plates 442' and 44 h.

As best seen in FIGS. 1 and 7, the right-hand or discharge end of thegrinding mill, as viewed in FIG. I, is provided with a dischargediaphragm assembly in which the subassembly generally indicated at 30',to be described more fully hereinafter, and comprising the grates, wearplates, discharge cone, and lifters are assembled in a manner generallysimilar to the liner assembly 30 located at the feed end of the grindingmill.

As seen in FIGS. 1 and 7, the grinding mill is provided at the dischargeend with a discharge casting assembly generally indicated at 86,positioned contiguous the axially inner end of the end flange H6 at thedischarge end of the grinding mill and comprising a plurality ofsuperposed tiers of outer discharge castings 87, middle or intermediatedischarge castings'SS, and inner discharge castings 89. Contiguousdischarge castings 87, 88, in a given tier have wedge bolts (not shown)positioned therebetween to hold the castings in tightly assembledrelation in a direction circumferentially of the discharge end of thegrinding mill. A ring liner 90 which serves as a wear surface is 1secured to the inner surface of the end plate 22' of the grinding millradially inwardly of the assembly 86 of the outer discharge castings,middle discharge castings, and inner discharge castings.

A discharge cone generally indicated at 91 formed of a plurality ofarcuate castings joined to complete a 360 arc is secured in position bywedge bolts 92. The wedge bolts 92 are generally similar to those usedfor discharge castings 87 and 88 and are received in cooperatingrecesses in contiguous discharge cone castings. The wedge bolts passthrough flanges 93 of the cone castings, through ring liner 90, andthrough wall 22' of the mill. The wedge portions of the bolts engagecontiguous discharge cone castings to maintain the discharge conecastings in tightly assembled relation.

A retainer ring 95, preferably made in several 180 degree sections, isbolted to the radially inner periphery of discharge cone 91, and oncethe discharge cone castings are adjusted in the final assembly, the 180sections of retainer ring 95 are welded together. The retainer ring 95provides a supplemental radial retaining action preventing radialmovement of the discharge cone and wear plate casting assembly.

As will be explained more fully, the radially outer edge of thedischarge cone 91 cooperates with the radially inner edge of the wearplate assembly to hold the wear plate assembly in position.

The subassembly comprising the grates and wear plates will now bedescribed. As best seen in FIGS. 1 and 7, a plurality of grate castingseach generally indicated at are mounted in contiguous relation to eachother about a 360 arc interiorly of the grinding mill. The radiallyouter edges of the grate castings 100 abut against the radially innersurface of a filler ring 36' similar to the filler ring 36 previouslydescribed at the feed end of the grinding mill. The radially outer edgesurfaces of the grates 100 are arcuate to match the arcuate curvature ofthe radially inner surface of the filler ring 36'. It will be noted thatthe discharge castings 87, 88, 89 include integral axially and radiallyextending flange portions 102 which serve to space the right-hand axialface of the discharge grates 100, with respect to the view of FIG. 1,and of the wear plates stacked thereon, from the axially facing surfaceof the discharge casting assembly 86, whereby to define a dischargechamber 104 between the grate and wear plate assembly 30 and surfaces ofthe discharge casting assembly generally indicated at 86. It will benoted that the radially outermost discharge castings 87 include anintegral circumferentially extending flange 103 which defines the bottomof discharge chamber 104.

The grates 100 are provided with passages 106 therethrough ofappropriate size whereby the material being ground in the grinding millwhen it reaches the appropriate size will pass through the passage I06and into the discharge chamber 104 defined by the space between thegrate and wear plate subassembly 30' and the discharge casting assembly86. The material passing into chamber 104 ultimately passes outwardlythrough the discharge trunnion 24' of the grinding mill.

As seen in FIG. 7, a lifter bar 108 is interposed between each pair ofcontiguous grates 100. A tier comprising a plurality of intermediatewear plates 110 similar to the wear plates 44 previously described atthe feed end of the grinding mill, are stacked above or radiallyinwardly of the grates 100, as best seen in FIG. 7, the intermediatewear plates extending for 360 around the inner periphery of the grindingmill. Lifter bars 108 are provided between each pair of contiguous wearplates 1 10. In a similar manner, a tier comprising a plurality ofradially inner wear plates I12 are positioned in a stacked relation tothe wear plates 110, and a lifter bar 108 is positioned between eachpair of contiguous ear plates 112. The lifter bars I08 disposed betweengrates 100, between contiguous intermediate wear plates 110, and betweenthe wear plates 112 are all respectively similar to the lifter bar 60shown in FIG. 4 of the drawings. Similarly, each pair of contiguousgrates, intermediate wear plates, and radially inner wear plates, may berecessed in the same manner as described in connection with the wearplates Me and 44!: in the view of FIG. 4 to receive the lifter bar 108.Alternatively, the lifter bars I08 and the wear plates may cooperate inthe manner shown in FIG. 5 of the drawings. Each lifter bar 108 is heldin place by a bolt such as the bolt 80, and by a nut such as the nut 82shown in the view of FIG. 4, the bolt passing through the lifter bar,through flanged regions 102 (FIG. 7) of the castings of the dischargesubassembly 86, and through the end flange 16 of the grinding mill.

The castings of the discharge cone 91 are respectively provided on theradially outer periphery thereof with grinding pads 114 which areadapted to engage a recessed or stepped area 116 at the radially inneredge of the radially inner wear plates 1 12. Before installing theradially inner wear plates 112, the vertical or radial dimension of thewear plates 112 is measured, and knowing this dimension, the integralgrinding pads 114 located on the already installed discharge conecasting 91 can be ground or trimmed to the exact dimensionalrequirements to maintain the plurality of stacked tiers of grates 100,intermediate wearing plates 110, and radially inner wearing plates 112in tightly assembled relation in the same manner as described inconnection with the wear plates 44 of the feed end as shown in the viewsof FIGS. 1, 2 and 3.

The wear plates 44 at the feed end of the mill (FIGS. 1, 2 and 3) areprovided with supplemental lifter bars 45 cast integrally with the wearplates. Similarly, the wear plates 110 and 112 at the discharge end ofthe mill are provided with supplemental lifter bars 115 cast integrallywith the wear plates. The integral lifter bars 45 and 115 supplement theaction of the respective lifter bars 69 (FIGS. 1, 2 and 3) and 108 (FIG.7).

There is shown in FIG. 8 a fragmentary view of a modified arrangementwhich may be used in place of the grinding pads such as the grindingpads 47, 50 and 54 of FIG. 2 and the grinding pads 114 of FIG. 7 forholding the wear plate assembly at the feed end of the mill or the grateand wear plate assembly at the discharge end of the mill in tightlyradially assembled and pyramided relation.

As seen in FIG. 8, a pair of wedges 1 18 and 120 of a suitable metal arepositioned in the clearance space between the radially innermost edge ofthe radially innermost set of wear plates 144 and the pinned linermember 146. The two wedges 118 and 120 have their facing taperedsurfaces tapering in opposite axial directions so that wedge 118, forexample, may be driven to the left, with respect to the view shown inFIG. 8, to increase the wedging action of the two combined wedges withrespect to members 144 and 146. In a similar manner, as shown in theview of FIG. 9 a single T-shaped wedge 122 may be driven between thefacing surfaces of the radially innermost wear plate or liner member 144and the pinned liner member 146 to provide a wedging action which holdsthe assembly of wear plates in tightly assembled relation.

It will be understood of course that the pair of wedges 118 and 120 orthe single T-shaped wedge 122 may be used in any position in which agrinding pad such as 47, 50, 54 or 114 would otherwise be used, and aplurality of pairs of wedges 118-120 or a plurality of T-shaped wedges122 would be used between the plurality of radially innermost wear platemembers 44 and the contiguous pinned liners such as 46 (FIGS. 1, 2 and3) at the feed end of the grinding mill, or between the wear plates 112and the discharge cone 91 (FIGS. 1 and 7 With the wedges 118 and 120(FIG. 8) or with the T-shaped wedge 122 (FIG. 9) properly adjusted toobtain the required holding action on the liner assemble 30 or 30', aspreviously described, a suitable weld such as a tack weld, for example,may be positioned over the axially inner end of the wedge to preventmovement of the wedge means away from its proper adjusted position.

The manner of holding the wear plate assemblies or grate and wear plateassemblies in tightly assembled relation in accordance with theinvention hereinbefore described has numerous advantages. One importantadvantage is that the end liner or wear plate assembly, while it obtainssome supplementary clamping action from the lifter bars 60, will not beaffected immediately if a lifter bar becomes detached from or loose inits mounting since'the primary clamping action depends upon theengagement of the grinding pads (FIGS. l-7) or the wedges (FIGS. 8 and9) with the liner assembly.

A further advantage of the construction hereinbefore described is thatthe use of grinding pads on the individual wear plates or liner membersconstituting the end liner assembly is obviated, and the entireadjustment action for providing radial compression of the wear plateassembly is obtained between the radially inner end of the wear plateassembly and a pinned liner or other member which is stationary withrespect to the grinding mill structure.

A further advantage of the construction is that the liner members orwear plates may have straight edges at the radial ends thereof whichallows for more economical casting in the foundry and which permitseasier inspection by means of a template. Still a further advantage isthat the construction permits readjustment of the number of wear platesor liner elements when a wearing pattern has been established in thegrinding mill. Still a further advantage of the construction is that thewear plates or liner members do not have to be precisely dimensioned ina circumferential direction. Still a further advantage of theconstruction is that the liner members or wear plates cannot shiftduring running conditions of the mill.

From the foregoing detailed description of the present invention, it hasbeen shown how the objects of the invention have been obtained in apreferred manner. However, modifications and equivalents of thedisclosed concepts such as readily occur to those skilled in the art areintended to be included within the scope of this invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. An end liner assembly adapted to be mounted inside an axial end of arotary grinding mill, comprising a plurality of radially superposedtiers of liner members, the radially outermost end of said plurality oftiers bearing against means rigid with respect to said mill, and meanscarried by said mill and engaging the radially innermost end of saidplurality of tiers and holding said plurality of tiers in radiallycompressed relation.

2. An end liner assembly as defined in claim 1 including a first memberrigidly fixed to the axial end of the grinding mill, and means carriedby the radially outer end of said first member engaging the radiallyinner end of said plurality of tiers to hold said plurality of tiers inradially compressed relation.

3. An end liner assembly as defined in claim 2 in which said meanscarried by the radially outer end of said first member is a grindingpad.

4. An end liner assembly as defined in claim 1 including a first memberrigidly fixed to the axial end of the grinding mill, said first memberincluding a radially outer edge lying radially inwardly of the radiallyinnermost end of said plurality of tiers, and means interposed betweensaid radially outer edge and said radially innermost end for holdingsaid plurality of tiers in radially compressed relation.

5. An end liner assembly as defined in claim 4 in which said meansinterposed between said radially outer edge and said radially innermostend is a grinding pad adapted to be precisely dimensioned to hold saidplurality of tiers in radially compressed relation.

6. An end liner assembly as defined in claim 4 in which said meansinterposed between said radially outer edge and said radially innermostend is a wedge means adapted to hold said plurality of tiers in radiallycompressed relation.

7. An end liner assembly as defined in claim 1 which is positioned atthe feed end of the grinding mill.

8. An end liner assembly as defined in claim 1 which is positioned atthe discharge end of the grinding mill, and in which the radiallyoutermost of said plurality of tiers comprises at least one grate memberhaving passages therein to permit passage therethrough of material to adischarge passage.

9. An end liner assembly as defined in claim 2 which is positioned atthe discharge end of the grinding mill. and in-which said first memberis the discharge cone of the grinding mill.

10. An end liner assembly as defined in claim 1 in which a given tiercomprises a plurality of circumferentially spaced liner members, lifterbar means positioned between contiguous liner members in a given tier,and means for holding said lifter bar means in clamped engagement withsaid contiguous liner members.

11. An end liner assembly as defined in claim 10 in which contiguousliner members and the lifter bar means positioned therebetween in agiven tier are contoured to'permit said lifter bar means to clampinglyengage said contiguous liner members, and means securing said lifter barmeans in clamped engagement with said contiguous liner members.

12. In combination, a rotary grinding mill, an end liner assemblyadapted to be mounted inside an axial end of said grinding mill, saidend liner assembly comprising a plurality of radially superposed tiersof liner members, the radially outermost end of said plurality of tiersbearing against means rigid with respect to said mill, and means carriedby said mill and engaging the radially innermost end of said pluralityof tiers and holding said plurality of tiers in radially compressedrelation.

13. The combination defined in claim 12 including a first member rigidlyfixed to the axial end of the grinding mill, and

means carried by the radially outer end of said first member engagingthe radially inner end of said plurality of tiers to hold said pluralityof tiers in radially compressed relation.

14. The combination defined in claim 13 in which said means carried bythe radially outer end of said first member is a grinding pad.

15. The combination defined in claim 12 including a first member rigidlyfixed to the axial end of the grinding mill, said first member includinga radially outer edge lying radially inwardly of the radially innermostend of said plurality off tiers, and means interposed between saidradially outer edge and said radially innermost end for holding saidplurality of tiers in radially compressed elation.

16. The combination defined in claim 15 in which said means interposedbetween said radially outer edge and said radially innermost end is agrinding pad adapted to be precisely dimensioned to hold said pluralityof tiers in radially compressed relation.

17. The combination defined in claim 15 in which said means interposedbetween said radially outer edge and said radially innermost end is awedge means adapted to hold said plurality of tiers in radiallycompressed relation.

1. An end liner assembly adapted to be mounted inside an axial end of a rotary grinding mill, comprising a plurality of radially superposed tiers of liner members, the radially outermost end of said plurality of tiers bearing against means rigid with respect to said mill, and means carried by said mill and engaging the radially innermost end of said plurality of tiers and holding said plurality of tiers in radially compressed relation.
 2. An end liner assembly as defined in claim 1 including a first member rigidly fixed to the axial end of the grinding mill, and means carried by the radially outer end of said first member engaging the radially inner end of said plurality of tiers to hold said plurality of tiers in radially compressed relation.
 3. An end liner assembly as defined in claim 2 in which said means carried by the radially outer end of said first member is a grinding pad.
 4. An end liner assembly as defined in claim 1 including a first member rigidly fixed to the axial end of the grinding mill, said first member including a radially outer edge lying radially inwardly of the radially innermost end of said plurality of tiers, and means interposed between said radially outer edge and said radially innermost end for holding said plurality of tiers in radially compressed relation.
 5. An end liner assembly as defined in claim 4 in which said means interposed between said radially outer edge and said radially innermost end is a grinding pad adapted to be precisely dimensioned to hold said plurality of tiers in radially compressed relation.
 6. An end liner assembly as defined in claim 4 in which said means interposed between said radially outer edge and said radially innermost end is a wedge means adapted to hold said plurality of tiers in radially compressed relation.
 7. An end liner assembly as defined in claim 1 which is positioned at the feed end of the grinding mill.
 8. An end liner assembly as defined in claim 1 which is positioned at the discharge end of the grinding mill, and in which the radially outermost of said plurality of tiers comprises at least one grate member having passages therein to perMit passage therethrough of material to a discharge passage.
 9. An end liner assembly as defined in claim 2 which is positioned at the discharge end of the grinding mill and in which said first member is the discharge cone of the grinding mill.
 10. An end liner assembly as defined in claim 1 in which a given tier comprises a plurality of circumferentially spaced liner members, lifter bar means positioned between contiguous liner members in a given tier, and means for holding said lifter bar means in clamped engagement with said contiguous liner members.
 11. An end liner assembly as defined in claim 10 in which contiguous liner members and the lifter bar means positioned therebetween in a given tier are contoured to permit said lifter bar means to clampingly engage said contiguous liner members, and means securing said lifter bar means in clamped engagement with said contiguous liner members.
 12. In combination, a rotary grinding mill, an end liner assembly adapted to be mounted inside an axial end of said grinding mill, said end liner assembly comprising a plurality of radially superposed tiers of liner members, the radially outermost end of said plurality of tiers bearing against means rigid with respect to said mill, and means carried by said mill and engaging the radially innermost end of said plurality of tiers and holding said plurality of tiers in radially compressed relation.
 13. The combination defined in claim 12 including a first member rigidly fixed to the axial end of the grinding mill, and means carried by the radially outer end of said first member engaging the radially inner end of said plurality of tiers to hold said plurality of tiers in radially compressed relation.
 14. The combination defined in claim 13 in which said means carried by the radially outer end of said first member is a grinding pad.
 15. The combination defined in claim 12 including a first member rigidly fixed to the axial end of the grinding mill, said first member including a radially outer edge lying radially inwardly of the radially innermost end of said plurality off tiers, and means interposed between said radially outer edge and said radially innermost end for holding said plurality of tiers in radially compressed elation.
 16. The combination defined in claim 15 in which said means interposed between said radially outer edge and said radially innermost end is a grinding pad adapted to be precisely dimensioned to hold said plurality of tiers in radially compressed relation.
 17. The combination defined in claim 15 in which said means interposed between said radially outer edge and said radially innermost end is a wedge means adapted to hold said plurality of tiers in radially compressed relation. 